In order to effectively generate printed images using the various ink transfer techniques and systems (with primary but not necessarily exclusive reference to thermal inkjet technology), ink-receiving print media materials must be employed which are capable of efficiently accomplishing this goal. Ideally, to achieve maximum efficiency, print media materials should be able to provide numerous advantages and benefits including but not limited to (1) a high level of light-fastness, with the term “light-fastness” being generally defined herein to involve the capacity of a print media product to retain images thereon in a stable fashion without substantial fading, blurring, distortion, and the like over time in the presence of natural or made-made light; (2) rapid drying times in order to avoid smudging and image deterioration immediately after printing is completed due to contact with physical objects and the like; (3) the fast and complete absorption of ink materials in a manner which avoids image distortion caused by color bleed (namely, the undesired migration of multi-colored ink components into each other) and related difficulties; (4) a highly humid-fast character (with the term “humid-fast” being generally defined to involve the ability of a print media product to produce a stable image with little or no fading, run-off, distortion, and the like when the image is placed in contact with moisture, humidity, and the like (also known in a substantially equivalent fashion as “water-fastness”)); (5) the generation of “crisp” images with a distinct and defined character; (6) the ability to produce printed products which are substantially “smear-fast”, with this term being generally defined to comprise the production of images that will not exhibit smearing, blurring, and the like when rubbed or otherwise physically engaged with a variety of objects ranging from the components of the printing apparatus being employed to the print operator's hands, fingers, and the like; (7) the control of an undesired condition known as “ink-coalescence” which is defined herein to involve a phenomenon wherein wet ink droplets applied to a printing medium fail to spread sufficiently to eliminate the unprinted (e.g. open) space between the droplets, thereby causing significant image deterioration problems which are primarily manifested by the increased “graininess” of the image; (8) the capacity to generate printed images with desired levels of gloss wherein the final product is characterized by uniform gloss levels throughout the entire image in order to achieve a professional and aesthetically-pleasing printed media sheet; (9) the ability to attain a high level of consistency during large-scale production regarding the overall surface characteristics of the completed media products; (10) low material costs which enable the print media products of interest to be employed for mass market home and business use; (11) chemical compatibility with a wide variety of ink formulations which leads to greater overall versatility; (12) excellent levels of image stability and retention over long time periods; (13) minimal complexity from a production, material-content, and layer-number standpoint (with as few required layers as possible being desirable) which leads to reduced fabrication costs and greater product reliability; and (14) a high level of gloss-control which is achievable in a rapid and effective manner during production through only minor adjustments in the manufacturing process. The term “gloss-control” is generally defined herein to involve the ability, during fabrication, to generate a print media product having high gloss levels for the production of photographic quality images if desired, a semi-gloss character if needed, or other gloss parameters. In particular, the manufacturing process should be highly controllable in order to achieve a variety of different gloss characteristics without requiring major adjustments in processing steps and materials.
A need remains for print media materials (namely, ink-receiving sheets or structures) which are able to capture and retain clear, distinct, and accurate images thereon that are likewise characterized by a number of specific benefits in combination. These benefits include but are not limited to items (1)-(14) recited above both on an individual and simultaneous basis in a substantially automatic manner (with the simultaneous achievement of such goals being of particular importance and novelty). The attainment of these objectives is especially important regarding the following specific items: a high level of humid-fastness, excellent light-fastness, an effective level of ink-coalescence control in order to prevent excessive “graininess” (namely, the undesired appearance of large “grain-like” elements in the printed product), and the generation of clear, durable, smear-fast, and distinct printed images.